After executing the IPCONFIG / ALL command it reports details of IP address and other details as well.
But after executing the NSLOOKUP command on Nodes, it displays unknown server name and on server displays server name LOCALHOST.

Then i try by adding IP address of Server in Prefered DNS Server address field in TCP/IP property sheet.

First to clear that i have already created active directory on my server.

Point 1. All three machine pinging to each other.
Point 2. As i informed earlier there is no workgroup but a domain and all machine on same domain.
Point 3. However there is no need to create the same user on all the machine because there is a domain. Then also i have check that by creating the user on each machine but the result is the same.

Further i want to inform you that, if i login locally on the machine not on Domain, then i can access the other machine, except the server, without giving the username and password of any kind.